modelSingleUTubeBoundaryCondition
Prescribed temperature at the outer boundary of a single U tube borehole
Information
This model computes the temperature boundary condition at the outer boundary of the borehole. It takes as an input the heat flow rate at the center of the borehole. This heat flow rate is averaged over the sample period. At each sampling interval, typically every one week, a new temperature boundary conditions is computed using the analytical solution to a line source heat transfer problem.
Implementation
The computation of the temperature change of the boundary is computed using the function Buildings.Fluid.Geothermal.Boreholes.BaseClasses.temperatureDrop.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.HeatTransfer.Data.Soil.Generic | matSoi | Thermal properties of the soil | |
| Modelica.Units.SI.Radius | rExt | 3 | Distance from the brine where the calculation is performed |
| Modelica.Units.SI.Height | hSeg | 10 | Height of the segment |
| Modelica.Units.SI.Temperature | TExt_start | 283.15 | Initial external temperature |
| Modelica.Units.SI.Time | samplePeriod | 604800 | Period between two samples |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | Q_flow | Heat flow rate at the center of the borehole, positive if heat is added to soil | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_b | port | Heat port |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| ExtendableArray | table | ExtendableArray() | Extentable array, used to store history of rate of heat flows |
| Modelica.Units.SI.HeatFlowRate | QAve_flow | Average heat flux over a time period |
Revisions
-
June 26, 2018, by Michael Wetter:
Replacedalgorithmwithequation. -
June 9, 2015 by Michael Wetter:
Revised model to provide start values and avoid a warning if Buildings.Fluid.Geothermal.Boreholes.Examples.UTube is translated using pedantic mode in Dymola 2016. This is for #426. -
September 27, 2013, by Michael Wetter:
Moved assignment ofstartTimetoinitial algorithmsection to avoid an error in OpenModelica. -
November 3 2011, by Michael Wetter:
Movedder(U) := Q_flow;from the algorithm section to the equation section as this assignment does not conform to the Modelica specification. -
September 9 2011, by Michael Wetter:
Movedequationsection intoalgorithmsection to make sure that the equations in thewhenblock are ordered correctly. -
July 28 2011, by Pierre Vigouroux:
First implementation.